Case 1 radiographic data. (A) The anteroposterior (AP) view and (B) the frog-leg lateral view showed a well-formed triangular radio-opacity (arrow) just adjacent to the prominent acetabular roof. (C) The axial computer tomography slice through the superior part of the hip joint clearly demonstrated the variable calcifications (arrow) in the origin of the rectus femoris. (D) Arthroscopic view of toothpaste-like calcified material (marked with arrows; SLAR, superolateral aspect of the acetabular roof). (E) Postoperative AP and (F) lateral views presented no residual calcium shadow.